Autonomic side effects of Botulinum toxin Type B intravesical injections: report of 4 cases and review of the literature.

Recently, intravesical injections of Botulinum toxin type B (BT-B) have been trialled in an attempt to treat detrusor overactivity. Use of Botulinum toxin A (BT.-A), for the same in the past, has been quite successful without many reported side effects. Soon after commencing the clinical use of BT-B, a side effect profile was noticed not reported with BT-A. A total of 20 patients with refractory detrusor overactivity were included in this randomized, double blind, placebo controlled, cross over trial. As per protocol, 5000 MU (1 ml) BT-B diluted to a volume of 20 mls with normal saline were injected in 10 different sites into the detrusor, sparing the trigone. We report four cases of autonomic side effects after these injections which strongly suggest clinically relevant systemic spread of the toxin.